Check if client is paired before creating pairing process

src/services/service.ts

@@ -132,6 +132,9 @@ export default class Services {
   }
 
   public async createPairingProcess(pairWith: string[], relayAddress: string, feeRate: number): Promise<ApiReturn> {
+    if (this.sdkClient.is_paired()) {
+      throw new Error('Device already paired');
+    }
     const myAddress: string = this.sdkClient.get_address();
     pairWith.push(myAddress);
     const newKey = this.sdkClient.get_new_keypair();